Infra-red printer



May 12, 1970 A. D- SCARBROUGH 3,512,158

INFRA-RED PRINTER Filed May 2, 1968 e Sheets-Sheet 1 DIRECTION OF TAPESCALE OF SEVEN CHARACTER GEN.

COMPUTER I \\//95 28 I 88 I 85 :0 c 0 82- Alfred D. Scarbrough dF/M BYsasa oz MXM ATTORNEY INFRA-RED PRINTER Filed May 2 1968 6 Sheets-Sheet 2TO DIODE AMPLIFIERS CHARACTER M5 GATES I /|O2 2 HO SCALE OF FIVE SCALEOF CLOCK COUNTER SEVEN COUNTER TIMING DECODE LEM CHARACTER DECODE Liji.

CHARACTER REGISTER SEQUENCER 2 1 1. 5 TO DIODE AMPLIFIERS I29 I30 I oBAND- f PASS I28 TIER DETECTOR I34 I36 COMMUNICATION SCALE OF LINK |3||32 SEVEN COUNTER I Lg? DET E CToR FILTER RESET M TIER IEQEGSR Alfred D.Scarbrough I4o BY A. D: SCARBROUGH 3, ,158

INFRA-RED PRINTER Ma 12, 1970 i Filed May 2, 1968 V 6 Sheets-Sheet 5 F6F7 F8 F9 FIO PH COMPUTER INVENIOR Alfred D. Scarbrough ATTORNEY Ma 12, 1970 IA. D. sAFBRouGH 3,512,158

. INFRA-RED PRINTER 6 Sheets-Sheet 4 Filed May 2, 1968 INVEN TOR AlfredD. Scarbrough F IIIIIIIIIIIIIIIIIIIIIII iwlllll wlllllillL ATTORNEY May1970 A. D. SCARBROUGH INFRA-RED PRINTER 6 Shets-Sheet 5 Filed May 2,1968 F3 F3 F4 I 1 F5 JNVENI'OR Alfred D. Scarbrough Wi -W ATTORNEY FiledMay 2, 1968 A. D. SCARB-ROUGH INFRA-RED PRINTER 6 Sheets-Sheet 6 WAITFOR START W m DATA IN MOTOR DELAY MOTOR REGISTER CLEAR SCAN COMPLETE wINVEN TOR Alfred D. Scarbrough ATTORNEY United States Patent US. Cl.346-76 15 Claims ABSTRACT OF THE DISCLOSURE The invention comprises aninfra-red printer using infrared emitters, such as infra-red emittingdiodes, as a source of heat to produce printing or graphical characterson heat-sensitive paper. In one embodiment, a heat-sensitive paper stripis pulled past seven infra-red diodes arranged in a line across thepaper to correspond to the seven vertical positions of a charactermatrix such as that used in display equipment. Selective energizing ofthe diodes irradiates the paper to correspond to a sequence ofcharacters that can be constructed from a dot matrix. Typically thediodes are pulsed, although they may be driven for longer durations toprint lines on the paper either by moving the paper past the diodes orby moving the diodes relative to the paper.

Short description of the invention Prior art printers use heated wiresor resistance elements to apply heat to heat-sensitive paper. Forexample, the US. Pat. No. 3,145,071 for a High Speed Thermal ContactPrinter, patented by Arthur W. Vance, uses heated wires, such as silverwires, to apply heat to a thermo-sensitive paper. The apparatus of theUS. Pat. No. 3,161,457 for Thermal Printing Units, issued to HansSchroeder et al., uses small resistors to generate heat and to apply theheat to the paper.

An example of commercially available thermally-sensitive material whichmay be marked by heat is the paper manufactured by Minnesota Mining andManufacturing Company which are marked under the trademark Thermo-Faxpaper.

With modern high speed computers, the speed at which the computers maybe read is limited by the speed at which the information may be printed.Infra-red emitting diodes have substantially no thermal inertia and theycan be turned on and off very rapidly. Consequently, because they may beturned on and oil very rapidly, the thermosensitive paper may be movedrapidly past the emitting diodes to generate information on the paperindicative of the information read out of the computer.

Infra-red emitting diodes, such as gallium arsenide diodes, areefficient and therefore generate little spurious heat. The heatgenerated is concentrated into a substantially monochromatic ray of highintensity infra-red radiation. The diode itself does not get hot becausethe generated energy is substantially all radiated.

Because the generated rays are monochromatic, they can easily befocused. Thus, for example, they may be focused into a beam of highintensity which prints the paper at a very rapid rate compared toprinters wherein the heat energy is spread over a wider spectrum and hasless intensity.

Some infra-red emitters emit parallel light beams in small concentratedbundles of energy, whereby no lens system is needed.

Infra-red emitters operate from relatively low power and voltagesources. Because of the low power and voltage requirements of theinfra-red emitters, they may be driven by transistorized circuitry.

Because of the high efficiency of the infra-red emitters and becausethey operate at a cool temperature, they have an inherently long life.

It is therefore an object of this invention to print on heat-sensitivepaper with infra-red radiation originating from a controlled infra-redsource.

It is a more particular object of this invention to achieve the aboveobject with infra-red emitting diodes.

It is still a more particular object of this invention to achieve theabove objects with infra-red emitters which are adapted to be controlledin response to electrical signals.

It is even a more particular object of this invention to control suchinfra-red emitters with transistorized circuitry.

It is another object of this invention to drive infra-red emitters withcircuitry arranged to produce pulses appropriate to generaterecognizable characters.

It is yet another object of this invention to achieve theabove-enumerated objects with transistorized circuitry which is adaptedto be responsive to logical signals.

It is a specific object of this invention to provide apparatus andcircuitry which is adapted to achieve the aboveenumerated objects.

Other objects will become apparent from the following description, takenin connection with the accompanying drawings in which:

Brief description of drawings FIG. 1 is a diagram of a rudimentarydevice of this invention;

FIG. 2 is a diagram of a device of this invention adapted to becontrolled by a character generator;

FIG. 3 is a sample of typical symbols in a 7 x 5 matrix which may beprinted by the device of this invention;

FIG. 4 is a more detailed block diagram of typical driving circuitry forinfra-red emitters, according to this invention;

FIG. 5 is a detailed block diagram of a typical frequency-shift keyingdriving circuitry for driving infrared emitters;

FIG. 6 is a specific embodiment of the character register, sequencer,and counters of FIG. 4;

FIG. 7 is a specific embodiment of the character decode means of FIG. 4;

FIGURE 8 is a specific embodiment of the timing decode gates of FIG. 4;

FIG. 9 is a specific embodiment of the character forming gates of FIG.4; and

FIG. 10 is a block diagram of the operation sequence of the apparatus ofFIG. 4.

Detailed descrip ion of invention Typically, characters are printed outin a 7 x 5 matrix of dots as shown, forexample, in FIG. 3. The drivingcircuitry shown herein is adapted to produce such characters. However,it should be stressed that the 7 x 5 dot matrix is shown for convenienceonly and that the invention is not to be limited to producing suchcharacters.

In FIG. 1, a control circuit 10, through an amplifier 12, drives aninfra-red emitter 14. The return circuit typically is through a commonterminal 16. Concurrently with the energizing of emitter 14, the controlcircuitry energizes the motor 18. Motor 18 drives a reel or spindle 20,winding heat-sensitive paper or tape off of the supply reel 22.

The control circuit may-for example-be a computercontrolled charactergenerator with associated equipment as shown in FIG. 2. Alternatively itmay be a paper or magnetic tape reader. Other examples of informationsources, such as memory drums, telemetering links, or electrictypewriters may be used.

The motor 18 may be a continuously energized motor, a stepping solenoid,or other intermittent motor.

The infra-red emitter 14 may, for example be a gallium arsenide diode.

The emitter 14, when energized, emits infra-red energy 24 which isfocused by a lens system 26 onto the heatsensitive paper 28. It shouldbe emphasized that the lens system 26 need not be used when the emissionof the emitter 14 produces the appropriate concentrated energy withoutsuch a lens system.

The lens system 26 may be a single or multiple lens. It need not bespherical. The criterion is that the radiation 24 be focused at thedesired point on the paper.

In FIG. 2, seven infra-red emitting diodes 30, 32, 34, 36, 38, 40, and42 are shown above the heat-sensitive paper 28. Radiation fromthese'diodes is shown focused onto the paper 28 by the cylindrical lens44.

The diodes are driven, respectively, by amplifiers such astransistorized amplifiers 46, 48, 50, 52, 54, 56, and 58 which, in turn,are excited by the outputs of AND distributing gates 60, 62, 64, 66, 68,70, and 72.

The output signals of character generator 74 are channeled to thedistributing gates. Timing signals are channeled from generator 74 intoa scale-of-seven counter 76 and are thence channeled to the distributinggates. Computer 75 is shown connected to determine the particularcharacter chosen by generator 74.

The character generator 74 is also shown controlling the motor 18, andhence the movement of the heat-sensitive tape 28.

Details of specific embodiments of the character generator connectionsare reserved for the discussion of FIGS. 4-10. I Typical figures printedonto tape 28 in a 7 x dot matrix are shown in FIG. 3f Notice that thedots are arranged in seven rows and five columns. For convenience ofdescription, number the columns from left to right, columns 1 through 5.Number the rows, consecutively, from bottom to top of the figure, rows 1through 7.

In the described embodiments, the dot positions are scannedone-at-a-time, starting with column 1, row 1; thence proceeding upcolumn 1 to row 7; thence to column 2, row 1, up column 2 to row 7;thence through columns 3, 4, and 5, in order, from roW 1 to row 7 in thesame fashion as in columns 1 and 2.

During movement of tape 28, the positions of the dot matrix come underthe infra-red diodes in the abovedescribed order. Should a signal betransmitted to the proper diode, a dot is produced on the tape. Forexample, the position of column 1, row 1, first moves into positionunder diode 42. Should a pulse of energy be received by diode 42 at thatmoment, a dot is produced in the column 1, row 1 position. A momentlater the tape 28 has advanced so that the column 1, row 2 position ofthe dot matrix has advanced under diode 40. Should a pulse of energy bereceived by diode 40 at that moment, a dot is produced in the column 1,row 2 position. The tape then advances to place, consecutively, thecolumn 1, row 3 under diode 38; column 1, row 4 under diode 36; column1, row 5 under diode 34; column 1, row 6 under diode 32; column 1, row 7under diode 30; column 2, row 1 under diode 42 Note that the row ofdiodes is turned slightly from a position directly across the tape 28,toward the direction of motion of the tape so that the diode 42 is inposition to produce a dot in'row 1 of the next column of the dot matriximmediately after the diode 30 is in position to produce a dot in row 7.Since the order of production of the dots in the dot matrix is known,each character which may be produced may be represented by a thirty-fivebit binary numeral in which, for example, the 1 indicates that a dot isformed in the consecutively indexed position, While the numeral 0"indicates that a dot is omitted in a particular position. Referring toFIG. 3, in which the numbers 80-95 indicate the consecutive dots to beproduced in the dot matrix, to print out the numeral 2 the print-outcommand can be represented by the binary sequence:

.To print out a character, the character generator 74 sends a series oftimed pulses to the scale-of-seven counter 76, causing the counter 76 todistribute the timing pulses to the gate amplifiers in the followingorder: 72, 70, 68, 66, 64, 62, 60, 72

Signals are also channeled from the character generator 74 to the motor18 to synchronize the tape movement with the timing signals.

A series of intermittent pulses are transmitted from generator 74 to allof the gates in synchronism with the timing signals. For example, whenthe numeral 2 is to be printed out, the pulses transmitted to all of thegates are intermittent in the above-mentioned pattern, i.e.:

wherein a 1 represents a pulse coinciding with a timing pulse, and a 0represents the absence of a pulse coinciding with a timing pulse.

There are many variations in the character generator. Obviously, ifdesired, thirty-five diodes could be positioned over the heat-sensitivepaper in the positions of the dots in the dot matrix. All of theappropriate diodes corresponding to the positions of desired dots couldthen simultaneously be energized.

One of the embodiments which prints the dots serially is shown in FIG.4. The computer 75 produces command signals indicating the character tobe written out. A typical output of computer 75 might be six channels inparallel adapted to set a register means such as the character register104. Typically, the character register cells are flip flops wherein theoutput signals, F and F represent two complementary outputs, e.g. F istrue and F is false when the-flip flop stores a 1, and F is false and Tis true when the flip flop stores a 0. A six channel computer output isshown, for example, in FIG. 6 in which the six signals are designated bythe lines 326, 327, 328, 329, 330, and 331'. The signals 326-331 areconnected to the character register 104 which generates twelve signals,F6, W, F7, W, F8, F8, F9, F5, F10, W, F11, and F11. The signals F6-F11are channeled into a sequencer means such as the sequencer 108 whichstarts the motor 18 when any signal other than (F6) (F7) (F8) (F9) (F10)(F11) is sensed, such term being true only when the register 104 storesonly zeros. All of the output signals of register 104 are channeled intoa decoding means such as the character decode means 106. The outputsignal of the sequencer 108 is connected to AND gate 102 to control thechanneling of clock pulses from a timing means such as the clock into acounter means such as the scale-of-seven counter 118. When the desiredcharacter is completely printed, a clear signal is delivered from thesequencer 108 to clear the character register 104.

The timing pulses delivered by clock 100, through gate 102 to thescale-of-seven counter causes the scale-of-seven counter to indexthrough its seven states.

The scale-of-seven counter 118 may, for example, comprise three flipflops producing outputs designated F0, F0, F1, W, F2, F2. Any sevenstates of these signals may be used as the outputs of the scale-of-sevencounter 118. For explanation purposes, as shown in FIG. 8, the followingcodes have been chosen as outputs of the counter 118:

The binary output 110 of the counter 118 is connected to reset counter118 into its 000 state and to send a pulse to the scale-of-five counter120. Counters 118 and 120, together, may be considered to be a countermeans.

The scale-of-five counter 120 may, for example, comprise three flipflops producing outputs F3, F3, F4, fi, F5, F5. Any five states of thesesignals may be used as the outputs of the scale-of-five counter 120. Forexplanation purposes, as shown in FIG. 8, the following codes have beenchosen as outputs of the counter 120:

The binary output 100 of counter 120 is connected to reset counter 120into its 000 state.

The scale-of-seven counter 118 may be adapted, as in FIG. 4, to produceseven signals which are produced in ordered sequence in synchronism withthe timing pulses of clock 100. Alternatively, as shown in the specificembodiment of the timing decode gate of FIG. 8, the same signals may beproduced in the timing decode gates 116 (also considered to be part ofthe counter means).

The timing decode gates 116 are adapted to produce thirty-five timedsignals, distributed in sequence upon thirty-five conductors showngenerally at 110. That is, the first signal in the sequence is channeledto the first conductor, the second signal to the second conductor, andso on through the thirty-five signals and conductors.

The character decode means 106 is adapted to produce a signal on onlyone of the sixty-three conductors shown generally at 112. That is, thepresence of a signal upon a particular conductor of the set 112 acts asa command signal to the character forming gates 114 to control theparticular sequence of signals produced by gates 114 to cause theinfra-red emitters to produce a particular character upon tape 28 in thedot matrix shown in FIG. 3.

The combination of signals from conductors 110 and 112 causes apermanent storage means such as the character forming gates 114 toproduce a timed sequence of signals such as that needed to form thecharacter 2, Le: 11100101001001100100110010011000110.

The signals delivered by the scale-of-seven counter 118 (oralternatively by the timing decode gate 116) to the distributing gates60-72, are connected so that the first timing signal in each set ofseven sequenced timing signals is channeled to gate 72, the second togate 70, the third to gate 68, and the fourth, fifth, sixth, and seventhto gates 66, 64, 62, and 60, respectively.

The basic operation diagram is shown in FIG. 10. The apparatus of FIG. 4first waits for data from the computer 75. The data is placed into theregister 104 and the motor 18 is started. After a short delay, caused bythe sequencer 108, signals are sent to the gate 102 (the motor 18 isthen up to speed and running) to cause the circuitry to drive theinfra-red emitters to print the desired character. When the print out ofthe character is complete, the register 104 is cleared by the sequencer108 and the apparatus again waits for data from the computer 75.

Referring now to FIG. 6, there is shown a typical sequencer 108. Insequencer 108, the JK flip flops 304 and 310 have outputs which, forconvenience, are designated F12, F 1'2 F13, F1 3. The presence of asignal on the J input of flip flop 304 sets flip flop 304 into its F12state (i.e. F12 true and T12 false). The presence of a signal on the Kinput sets flip flop 304 into its F 12 state. Similarly, the presence ofa signal on the J input of flip flop 310 sets that flip flop into itsF13 state. A signal on the K input sets the flip flop into its F 13state.

The F6-F11 signals from the register 104are connected to the inputterminals of an OR gate 300. The out- 6 put of gate 300 is connectedthrough AND gate 302 to the J input of flip flop 304. The K input offlip flop 304 is connected to AND gate 340 which has a true output whenthe end of a matrix scan is reached.

The F12 output of flip flop 304 is connected to the input of AND gate102, to amplifier 306, and through time delay means 308 to the J inputof flip flop 310. The W output of flip flop 304 is connected to theinputs of AND gates 302 and 314, and through time delay means 312 to theK input of flip flop 310.

The F13 output of flip flop 310 is connected to the inputs of AND gates102 and 314. The F 13 output of flip flop 310 is connected to the inputof gate 302.

When the register 104 is set into any condition except 000000, the gate300 delivers a signal to gate 302. Provided the flip flops are in theirzero or false state, i.e. provided m and m signals exist, the gate 302delivers a signal to the J input of flip flop 304 setting it into itsone or true state, i.e. an F12 signal is produced.

The production of an F12 signal causes the motor 18 to be actuated bythe amplifier 306. After a short delay, by means 308, to allow the motorto accelerate, the F12 signal appears on the J input of flip flop 310which sets flip flop 310 into its F13 state. With flip flops 304 and 310producing signals F12 and F13, gate 102 is opened to allow timingsignals from clock to be channeled to counter 118. When thirty-fivepulses have been delivered by clock 100 to register 118, a signalappears on AND gate 340 which sets flip flop 304 into its 1 1'? state.

The setting of flip flop 304 into its FE state causes gate 314 (becausean F13 signal is still present) to deliver a clearing signal to register104.

After a short delay to allow the clearing signal, time delay means 312allows the FT? signal to reset flip flop 310 into its F11: state. Thesequencer 108 is then ready to receive the next signal from register 104and to repeat the operation.

A typical character decode means 106 is shown in FIG. 7. In FIG. 7,eight AND gates, shown at 320, are each adapted to receive three inputsof different permutations of F6 or 1 6, F7 orw, and F8 or F8. Thus thegates 320, from left to right in FIG. 7 are responsive, respectively tothe following inputs F6 F7 F8 The eight AND gates, shown at 322, areeach adapted to receive three inputs of different permutations of F9 orT9, F10 or F10, F11 or F'fi. Thus the gates 322, from bottom to top inFIG. 7, are responsive, respectively to the following inputs:

F9 F10 Fl].

seven AND gates of the matrix 324. Eachof the seven AND gates also hasconnected to its input terminals an output connection of a different oneof the set for gates 322, except for the bottom gate which has inputsignals TFO) Tm (F11). Thus for each combination of F6 or F6, F7 or 1 7,F8 or F8, F9 or F, F10 or F10, F11 or iii, except T87 TFT F TF5? F107F117, there exists an AND gate in the matrix 324 which produces asignal. For any particular signal on register 104, except 000000, thereis one and only one of the conductors 112 energized.

A typical timing decode gate matrix 116 is shown in FIG. 8. In FIG. 8,seven AND gates, shown at 330, are each adapted to receive three inputsof different permutations of F0 or F0, F1 or E, F2 or W. The gates 330,from left to right in FIG. 8, are responsive respectively to thefollowing inputs:

F0 F1 F2 F3 F4 F5 The output of each of the gates 330 is connected tofive AND gates of a matrix 334 of thirty-five AND gates. Each of thefive AND gates also has connected to its input terminals an outputconnection of a different one of the five gates in the set 332. Thus foreach combination of F0 or W, F1 or E, F2 or W, F3 or F3, F4 or F4, F5 orW (except those of the form lllxxx, xxxlOl, xxxllO, and xxxlll, where xis a 1 or *0) there exists an AND gate in the matrix 334 which producesa signal. The outputs of the matrix 334 are thirty-five conductors 110.The thirty-five conductors 110 are consecutively energized insynchronism with the clock pulses delivered from clock 100.

It is apparent that the gates 330 could have been part of thescale-of-seven counter 118, with the outputs of gates 330 connected,respectively, to the gates 60-72 .(FIG. 4).

It is also apparent that the gates 332 could have been part of thescale-of-five counter 120. Instead of connecting the counters 118 and120 with an AND gate 119 (see FIG. 6), the output of the right hand gateof gates 330 could have delivered pulses to counter 120.

A typical character forming gate circuit 114 is shown in FIG. 9. In FIG.9, the conductors 110 are displayed or ordered so that the conductorreceiving the first timing pulse is at the top, the conductor receivingthe second pulse is next, and so on down the column of conductors untilthe last conductor receives the last pulse.

Only a single conductor 341 of the conductors 112 is shown, carrying acontrol signal to print out the character 2. The first conductor 340 ofconductor set [110 is connected to an AND gate 342. The gate 342 is alsoconnected to the conductor 341 of the set of conductors 112. Theconductor 341 is also connected to other AND gates shown generally at344. The set of gates 344 has a number of gates equal to the number ofdots in the character 2. The gates of the set 344 are connected to thesequentially pulsed conductors so that a pulse is delivered at theproper time to cause the infra-red emitters to'print out the dots of thecharacter 2.

The outputs of the gates 344 are connected to a bank of OR gates 346 sothat whenever one of the gates 344 is energized, a signal appears at theoutput terminal 348.

Each of the other conductors (not shown) of the set of conductors 112 istypically connected to a set of gates similar to the set 344. The numberof gates in a particular set depends upon the number of dots of thecharacter to be printed out. The conductors of set 110 corresponding tothe time-sequenced dot positions in the particular chosen character tobe printed are connected to the AND gates.

It is apparent that other gate configurations could be used to reducethe number of gates.

It is also apparent that should there be dot positions in the dot matrixdescribed in connection with FIG. 3 which are never printed, theparticular conductors of set 110 corresponding to those dot positionsmay be omitted.

An alternative embodiment of the invention which is adapted to receivedot commands, for example, over a communication channel or link 128 isshown in FIG. 5. The particular circuit of FIG. 5 is adapted to receiveprint out commands from a frequency-shift-keying modulated signal. Thefrequency-shift-keying (FSK) signal comprises signals of twofrequencies, 1 and f2. In the shown embodiment, a frequency of 2corresponds to a command to print out a dot. A frequency of f1corresponds to a command not to print out a dot. The communication linkmay comprise a radio link, or an audio link. The signal may be anamplitude modulated signal, a pulse width modulated signal, a frequencymodulated signal, a pulse amplitude modulated signal, a pulse codemodulated signal, or any other signal carrying the required informationin FSK form.

The communication link 128 is connected to two filters 129 and 131 toseparate the t2 and f1 signals. The filters transmit signals to thedetectors and 132 which change the signals into substantially constantamplitude signals (of short duration, i.e. a pulse). The outputs of bothdetectors 130 and 132 are connected to an AND gate whose output isconnected to control a monostable multivibrator and to reset counter 138into its zero condition. The reception of a signal having both f1 and f2components at the beginning of a character, triggers the multivibrator,sending a pulse to the motor 18 of sufficient time duration to allow thedot matrix to be printed out. The outputs of detectors 130 and 132 areconnected to the inputs of the OR gate 136 whose output drives thescaleof-seven counter 138. Thus whenever a signal f2 (for a dot) or f1(to skip a dot) are received, the counter 138 indexes. The output ofdetector 130 is connected to the inputs of distributing gates 60-72 toprint a clot. The scale-of-seven counter 138 energizes only one of thegates 60-72 at a time in the sequence 72, 70, 68, 66, 64, 62, 60, 72,

Thus, when both f1 and f2 are simultaneously received, the motor 18 isstarted and the counter 138 is reset. The next signals received indexthe counter, and if they are f2 signals, they command the particulargate which is momentarily energized by counter 118 to send a signal toits infra-red emitting device to print out a dot.

It should be noted that variations of this embodiment are practical andcontemplated by this invention. For example, counter 138 may be reset bythe absence of both F1 and F2, and the motor 18 may be driven if eitherF1 or F2 is present. This could be accomplished by changing gate 134 toa NOR gate and constructing the monolife is assured. The emitters haveinsignificant thermal inertia, whereby they may rapidly be pulsed.Because of the concentrated power in the short-duration beams, lowenergy is required. Further, the emitters match the voltages andcurrents of transistorized or solid state driving circuitry.

There has also been provided by this invention, particular combinationsof driving circuitry which are particularly adapted for driving theinfra-red emitters.

What is claimed is:

1. In combination:

a movable strip of heat-sensitive material;

a plurality of infra-red emitters, adapted to emit infrared radiation;

means for directing infra-red radiation from said emitters ontopredetermined portions of said material;

emitter energizing means responsive to control signals,

for energizing said emitters in a predetermined manner, said emitterenergizing means comprising;

means for receiving and storing said control signals; means for storingcharacter programs;

means for converting said stored control signal into a command signaladapted to extract a predetermined character signal sequence from saidpermanent storage means;

timing means;

distributing means, connected to receive said character signal sequenceand to deliver said signals to said emitters;

means connected to receive signals from said timing means and to deliversignals to said permanent storage means to time the production of saidcharacter signal sequence, and to said distributing means to distributesaid character signal sequence consecutively, in predetermined order tosaid emitters; and

motor means responsive to said emitter energizing means for driving saidmaterial in synchronism with the energizing of said emitters to printout characters upon said material in response to said control signals.

2. In combination:

a movable strip of heat-sensitive material;

a plurality of infra-red emitters, adapted to emit substantiallymonochromatic infra-red radiation, ar. ranged in a row which is tiltedfrom a direction normal to the direction of motion of said material,toward said direction of motion;

means for directing infra-red radiation from said emitters ontopredetermined portions of said material;

emitter energizing means responsive to control signals,

for consecutively energizing said emitters in a predetermined sequence,said emitter energizing means comprising;

register means for receiving and storing said control signals;

permanent storage means for storing character programs;

decoding means for converting said stored control signal into a commandsignal adapted to extract a predetermined character signal sequence fromsaid permanent storage means;

timing means;

distributing means, connected to receive said character signal sequenceand to deliver said signals to said emitters;

counter means, connected to receive signals from said timing means andto deliver signals to said permanent storage means to time theproduction of said character signal sequence, and to said distributingmeans to distribute said character signal sequence consecutively, inpredetermined order to said emitters; and

motor means responsive to said emitter energizing means for driving saidmaterial in synchronism with the energizing of said emitters to printout characters upon said material in response to said control signals.

3. Apparatus according to claim 2 and further comprising sequencermeans, connected to receive signals from said register means to startsaid motor means, to delay delivery of said timing signals, and to resetsaid register means into a state ready to receive a new control signal.

4. Apparatus according to claim 3 in which:

said permanent storage means comprises a plurality of character forminggates responsive to predetermined ones of signals from said timingmeans, and responsive to command signals from said decoding means.

5. Apparatus according to claim 3 in which:

said decoding means comprises a gate matrix adapted to receive binarysignals from said register means and to produce a signal upon a uniqueoutput conductor for predetermined ones of the binary combinationsreceived.

6. Apparatus according to claim 3 in which:

said timing means comprises a gated clock.

7. Apparatus according to claim 3 in which:

said distributing means comprises a plurality of distributing gates,connected to receive signals from said permanent storage means, and fromsaid counter means to distribute said signals from said storage means tosaid emitters in response to said signals from said counter means.

8. Apparatus according to claim 3 in which:

said counter means comprises a counter, and a plurality of timing decodegates arranged to deliver signals in sequence to a first plurality ofconductors connected to said permanent storage means, and to deliversignals in sequence to a second plurality of conductors connected tosaid distributing means.

9. Apparatus according to claim 3 in which:

said sequencer means comprises a pair of JK flip flops, the first saidflip-flop being responsive to a non-zero signal in said register meansto produce a signal to start said motor means, the second said flip-flopbeing responsive to a delayed signal from said first flip flop to gatepulses from said timing means to said counter means, said first flipflop being responsive to said counter means to reset at the end of thecount of said counter and to deliver a reset signal to said registermeans and a delayed reset signal to said second flip flop.

10. In combination:

a movable strip of heat-sensitive material;

a plurality of infra-red emitters, adapted to emit infrared radiation,arranged in a row which is tilted from a direction normal to thedirection of motion of said material, toward said direction of motion;

means for directing infra-red radiation from said emitters ontopredetermined portions of said material;

means, responsive to control signals, for consecutively energizing saidemitters in a predetermined sequence; and

motor means responsive to said means responsive to control signals fordriving said material in synchronism with the energizing of saidemitters to print out characters upon said material in response to saidcontrol signals,

said means responsive to control signals comprising:

means for separating control signals of a first fre quency from controlsignals of a second frequency;

detector means for detecting said first and second frequencies and forproducing first and second detected 11 signals indicative of thepresence of said first and second frequencies, respectively;

counter means, connected to be reset to its initial condition by signalschosen from the class consisting of the simultaneous reception of bothsaid detected signals, and of the absence of reception of either of saiddetected signals, and connected to count upon reception of only one ofsaid detected signals;

a monostable multivibrator, connected to be actuated by signals chosenfrom the class consisting of the simultaneousreception of both saiddetected signals, and of the reception of the first of a group of saiddetected signals, and connected to deliver an energizing signal to saidmotor means, the dwell time of said multivibrator in its unstablecondition being predetermined to allow complete print out of onecharacter; and

a plurality of distributing AND gates, connected to receive apredetermined one of said detected signals, and connected so that saidgates are consecutively gated by said counter means, said distributinggates channeling signals to said infra-red emitters.

11. Apparatus according to claim 10 and further comprising:

a communication link, connected to receive said control signals and todeliver them to said means for separating control signals, and adaptedto transmit frequency-shift-keying signals.

12. Apparatus according to claim 11 in which said means for separatingcontrol signals comprises:

a first and a second filter, connected to receive signals from saidcommunication link and to deliver signals to said first and seconddetector means, respectively.

13. Apparatus according to claim 12 in which:

said detected signals are channeled through an AND gate to the inputterminal of said multivibrator and to the reset terminal of said countermeans;

12 and in which said detected signals are channeled through an OR gateto the counting terminal of said counter means.

14. Apparatus according to claim 13 in which said counter means is ascale-of-seven counter, said distributing gates are seven in number, asignal is delivered by said counter to a different said distributinggate for each condition of said counter, and said predetermined one ofsaid detected signals is channeled to all of said distributing gates.

15. Apparatus according to claim 12 in which:

said detected signals are channeled through a NOR gate to the inputterminal of said multivibrator and to the reset terminal of said countermeans, said multivibrator beingresponsive to be triggered by thetransition from true to false by the output signal of said NOR gate; andin which said detected signals are channeled through an OR gate to thecounting terminal of said counter means.

References Cited UNITED STATES PATENTS 2,735,049 2/ 1956 DeForest317-235 2,909,973 10/1959 Koelsch et a1 954.5 3,085,132 4/1963 Innes17830 3,308,452 3/ 1967 Michel et a1. 340 -324 3,334,353 8/1967 Everest34676 3,341,857 9/1967 Kabell 346-l07 3,349,174 10/1967 Warschauer1786.7

JOSEPH W. HARTARY, Primary Examiner U.S. Cl. X.R.

